Hinge system for offshore structure

ABSTRACT

A hinge for use in a buoyant articulated off-shore platform. The hinge connects two members in a manner which permits rotation of one member relative to the other member through vertical planes while preventing horizontal rotation of the members relative to each other. The hinge is made up essentially of two parts: (1) a ball and socket joint and (2) torque elements arranged about the ball and socket joint.

United States Patent 9] Guy [4 1 May 29, 1973 75] Inventor:

[ HINGE SYSTEM FOR OFFSHORE STRUCTURE Arthur L. Guy, Houston, Tex.

[73] Assignee: Esso Production Research Company,

Houston, Tex.

[22-] Filed: Feb. 24, 1972 [21] Appl. No.: 229,155

Related U.S. Application Data [63] Continuation of Ser. No. 53,049, July 8, 1970.

[52] US. Cl. ..6l/46.5, 64/7, 287/21 [51] Int. Cl..... .E02b 17/00, E02d 27/04, F16c 11/06 [58] Field of Search 61/465, 46; 9/8;

[56] References Cited UNITED STATES PATENTS Primary Examine rJacob Shapiro Attorrzey-Th0mas B. McCulloch, Melvin F. Finckc, John Schneider [57] ABSTRACT A hinge for use in a buoyant articulated off-shore platform. The hinge connects two members in a manner which permits rotation of one member relative to the other member through vertical planes while preventing horizontal rotation of the members relative to each other. The hinge is made up essentially of two parts: (1) a ball and socket joint and (2) torque elements arranged about the ball and socket joint.

9 Claims, 4 Drawing Figures mm-wmmm 5,5

INVENTOR. ARTHUR L. GUY,

ATTORNEY.

IIINGE SYSTEM FOR OFFSHORE STRUCTURE This is a continuation of application Ser. No. 53,049, filed July 8, 1970. i j The present invention concerns a hinge connection 7 for use with articulated offshore oil and gas drilling and production platforms. These platforms comprise: a base which lies on the ocean floorand represents a fixed point; a joint which connects the base to the foot of a buoyant tower; buoyancy means for applying an upward force to the tower; and a platform deck for conducting operations. The platform oscillates in motion with the waves and the maximum inclination angle is limited by the size of the buoyancy means. The joint of the present invention is particularly advantageous in the subsea environment in which it is to be used since it is easier to fabricate, to operate, and to maintain than the universal joints in use or presently contemplated for use.

In accordance with the teachings of the invention, the hinge comprises a socket formed on one of two members;a ball element formed on the other member and arranged the socket; and aplurality of spaced apart interengaging lugs and recesses on the two members arranged about the ball element and the socket,

.1 each lug on theone member interengaging an opposing recess on the other member formed by two projections on the other member which engage such lug and prevent horizontal rotation of one member relative to the other member.

' BRIEF DEscRIPTIoN oF THE DRAWINGS FIG. 1 illustrates a hinge joint connecting a base member to a buoyant tower;

FIG. 2 is a view taken along lines 22 of FIG. 1;

FIG. 3 is a view taken along lines 3 3 of FIG. 2; and

FIG. 4 is a view taken along lines 4-4 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 4 there is shown a base member having fon'ned on it a ball element 11 and a pluralityof v spaced-apart curved torque projections 12 forminga recess 13 arranged about ball element 11. A second, member 1 4, shown in FIG. 1 connected to the base of-a buoyant tower 15, has formed in it a socket 16in which ball element 11 is interengaged and a plurality of spaced-apart lugs 17, each of which is located iri'one ofthe recesses 13. As shown in FIG. 4 a lubrication I port 19 may be provided in member 14. The torque projections 12 and recesses and lugs 17 are preferably forged or cast with the sizes and positions thereof selected to permit desired vertical angular rotation while preventing horizoiital rotation. Although not shown, the torque projections andlugs may be reinforced ,with brackets or stiffener plates. tThe sizes of the ball. and socket joint and thetorque projections and lugs will be selected as required by geometry and the forces they are required to transmit to achieve desired bearing unit stress levels in both the ball and socket joint and against the projections and lugs.

Referring to FIG. 1 the hinge joint is shown connected into a buoyant tower offshore structure. Base member 10. is secured to another base member 20 attached to the ocean floor and member 14 is secured to the base of the buoyant tower 15 which has connected to it within the interior thereof buoyancy, tanks 22. An

operations platform 23 is mounted at the uppermost end of buoyant tower 15 above the surface of the water 18. A plurality of conductor pipes 25 for the production of gas and oil are arranged about the periphery of buoyant tower 15. These conductor pipes connect into subsea production systems, not shown.

The complete joint may be kept lubricated by introducing lubricant at the top of the ball joint through lubrication port 19 by maintaining a proper head of oil or lubricant in the surface portion of the buoyant platform equal to the outside head of sea water. Lubrication can be performed at very nominal pressures.

In the buoyant tower platform arrangement the ball and socket joint transmits tension loads or compression loads from the buoyant tower 15 and the torque projections and lugs at the periphery of the base of the buoyant tower prevent rotation of the buoyant tower with respect to the base. The hinge permits vertical rotation through desired planes and eliminates bending moment at the base while preventing horizontal rotation.

Having fully described the apparatus, operation, objects, and advantages of my invention, I claim:

1. An articulated offshore structure comprising: a buoyant tower having a platform mounted thereon and having buoyancy means and a bottom member; a base member arranged on the sea floor; and a hinge connecting said base member to said bottom member of said buoyant tower such that rotation of said buoyant tower in vertical planes relative to said base member is permitted while rotation of said buoyant tower in a horizontal plane relative to said base member is prevented; said hinge comprising: a socket formed on one of said members; a ball element formed on the other of said members and arranged in said socket; and a plurality of interengaging lugs and recesses formed on said members and arranged about said ball element and said socket, each lug on one member interengaging an opposing recess formed by spaced apart projections on the other member at all positions of rotation of said buoyant tower in vertical planes relative to said base member, whereby said ball and socket joint transmit tension loads or compression loads from said buoyant tower to said base member and said lugs abut said spaced apart projections to prevent rotation of said buoyant tower in a horizontal plane relative to said bbase member. 2. An offshore platform as recited in claim 1 in which each of said recesses are formed by curved projections. 3. An offshore platform as recited in claim 2 in which said lugs are formed on said one member on which said socket is formed and said projections are formed on said other member on which said ball is formed.

4. An offshore structure having upper and lower sections and means connecting said upper and lower sections to permit movement of said upper section relative to said lower section wherein the improvement comprises:

a hinge connecting said upper section to said lower section, such that rotation of said upper section in vertical planes is permitted but rotation of said upper section in any horizontal plane is prevented;

said hinge comprising:

a socket formed on one of said sections;

a ball element formed on the other of said sections and arranged in said socket; and

a plurality of interengaginglugs and recesses formed on said sections and arranged about said ball element and said socket, each lug on one section interengaging an opposing recess formed by spaced apart projections on said other section, said lugs abutting said spaced apart projections to prevent rotation of said upper section in any horizontal plane relative to said lower section.

5. An offshore structure as recited in claim 4 in which four sets of lugs and recesses are arranged about said ball element and socket.

6. An offshore structure as recited in claim 4 in which each of said recesses is defined by two projections curved toward each other, the narrowest portion of each of said recesses being at the upper ends of said two projections.

7. An offshore structure as recited in claim 6 in which said lugs are formed on said section on which said socket is formed and said projections are formed on said section on which said ball is formed.

8. An offshore structure as recited in claim 7 including means for lubricating said ball and socket.

9. An offshore structure as recited in claim 8 in which said upper section comprises a buoyant tower and including a plurality of conductor pipes for the production of subsurface fluids arranged about the periphery of said buoyant tower. 

1. An articulated offshore structure comprising: a buoyant tower having a platform mounted thereon and having buoyancy means and a bottom member; a base member arranged on the sea floor; and a hinge connecting said base member to said bottom member of said buoyant tower such that rotation of said buoyant tower in vertical planes relative to said base member is permitted while rotation of said buoyant tower in a horizontal plane relative to said base member is prevented; said hinge comprising: a socket formed on one of said members; a ball element formed on the other of said members and arranged in said socket; and a plurality of interengaging lugs and recesses formed on said members and arranged about said ball element and said socket, each lug on one member interengaging an opposing recess formed by spaced apart projections on the other member at all positions of rotation of said buoyant tower in vertical planes relative to said base member, whereby said ball and socket joint transmit tension loads or compression loads from said buoyant tower to said base member and said lugs abut said spaced apart projections to prevent rotation of said buoyant tower in a horizontal plane relative to said base member.
 2. An offshore platform as recited in claim 1 in which each of said recesses are formed by curved projections.
 3. An offshore platform as recited in claim 2 in which said lugs are formed on said one member on which said socket is formed and said projections are formed on said other member on which said ball is formed.
 4. An offshore structure having upper and lower sections and means connecting said upper and lower sections to permit movement of said upper section relative to said lower section wherein the improvement comprises: a hinge connecting said upper section to said lower section such that rotation of said upper section in vertical planes is permitted but rotation of said upper section in any horizontal plane is prevented; said hinge comprising: a socket formed on one of said sections; a ball element formed on the other of said sections and arranged in said socket; and a plurality of interengaging lugs and recesses formed on said sections and arranged about said ball element and said socket, each lug on one section interengaging an opposing recess formed by spaced apart projections on said other section, said lugs abutting said spaced apart projections to prevent rotation of said upper section in any horizontal plane relative to said lower section.
 5. An offshore structure as recited in claim 4 in which four sets of lugs and recesses are arranged about said balL element and socket.
 6. An offshore structure as recited in claim 4 in which each of said recesses is defined by two projections curved toward each other, the narrowest portion of each of said recesses being at the upper ends of said two projections.
 7. An offshore structure as recited in claim 6 in which said lugs are formed on said section on which said socket is formed and said projections are formed on said section on which said ball is formed.
 8. An offshore structure as recited in claim 7 including means for lubricating said ball and socket.
 9. An offshore structure as recited in claim 8 in which said upper section comprises a buoyant tower and including a plurality of conductor pipes for the production of subsurface fluids arranged about the periphery of said buoyant tower. 